1. Field of the Invention
The present invention relates to encoding and decoding, and more particularly, to a scalable encoding and decoding apparatus, method, and medium for decoding a partially damaged encoding frame to perceive (recognize) audio information contained in the encoding frame by encoding a single frame in the order of a base layer, a first enhancement layer, and a second enhancement layer and also performing scalable encoding of the second enhancement layer.
2. Description of the Related Art
G.729 is a standard adopted by the ITU Telecommunication Standardization Sector (ITU-T) of the International Telecommunication Union (ITU). G.729, selected as a standard of a speech data encoding and decoding method, does not support scalable encoding. For example, when speech data is encoded from a low frequency band to a high frequency band using the method, the encoded speech data may be partially damaged when passing a channel, and in this case, the encoded speech data in the high frequency band is damaged prior to the encoded speech data in the low frequency band.
In a conventional speech standardization technology, when encoded speech data is partially damaged, a frequency band having no speech data may occur. Thus, according to a conventional speech encoding and decoding apparatus and method, when encoded speech data is partially damaged, a frequency band having no speech data may exist among frequency bands having speech information in encoding, and in this case, decoded speech data can be inaudible.